Roland, The challenge is based on a job that has (1) a number of individual sprinklers piped directly from "cross mains" and (2) a number of branch lines arranged like this - pipe, sprinkler, pipe, side outlet tee feeding two or more sprinklers, pipe, sprinkler, pipe, sprinkler. I've seen this hundreds of times and never thought there would be any question about these arrangements. Only the hydraulics counts. The AHJ is not in the U.S. I get a very disoriented on this one, but the logic is as follows:
1. An individual sprinkler must be attached to something called a branch line. In 2002 the term "directly" was used, in 2007 some language was added to expand this term to specific definitions of "directly". It's pretty clear directly means a single sprinkler, not more than one sprinkler on a single pipe. The pipe from the sprinkler to the branch line is either a sprig, drop, arm-over, or return bend. 2. Based on the definition of a branch line, the minimum number of heads on any branch line is two. The piece of pipe from the cross main to the first sprinkler is the "branch line". The pipe from the first sprinkler to the end sprinkler is defined as an arm-over. Using the strictest definition the last sprinkler on any branch line would be an arm-over I guess. 3. A cross main can only supply branch lines. Therefore, since the minimum number of heads on a branch line is two, a cross main cannot supply an individual sprinkler. 4. A feed main can only supply cross mains. See 3 above. 5. I'm assuming the sprig, drop, arm-over, or return bend cannot be called a branch line, regardless of length or number of fittings. 6. Figure A.3.5 illustrates a piping arrangement meeting the 3.5 definitions. No sprinklers supplied directly from cross mains or feed mains. Looks like the "riser nipple" should be deleted to make the diagram consistent with the list of definitions. Bill Brooks William N. Brooks, P.E. Brooks Fire Protection Engineering Inc. 372 Wilett Drive Severna Park, MD 21146 410-544-3620 Phone 410-544-3032 FAX 412-400-6528 Cell -------- Original Message -------- Subject: Re: Branch Lines / Cross Mains From: Roland Huggins <[EMAIL PROTECTED]> Date: Mon, November 26, 2007 10:50 am To: [email protected] Other than creating some confusion on seismic requirements, what difference does it make? what exactly is being challenged? I must confess I haven't thought a lot about this. Roland On Nov 23, 2007, at 9:18 AM, [EMAIL PROTECTED] wrote: > Todd Williams wrote: > > "Let's sit back and take a look at what we are trying to do here. > Install a sprinkler system to provide satisfactory protection against > fire in a particular building. Where or how the sprinklers are > connected to pipes should not be an issue, as long as adequate water > gets to the fire (with allowance for minimum pipe size, etc)." > > Agree completely, so why the explicit language in 2007 defining a > branch > line? As you state, it seems any pipe or any arrangement of piping > on a > hydraulically calculated wet pipe system is OK. > > Yes, this is an actual case - I couldn't have made this up by myself. > > Bill Brooks > > -------- Original Message -------- > Subject: RE: Branch Lines / Cross Mains > From: Todd Williams - FPDC <[EMAIL PROTECTED]> > Date: Fri, November 23, 2007 10:54 am > To: [email protected] > > Let's sit back and take a look at what we are trying to do here. > Install a sprinkler system to provide satisfactory protection against > fire in a particular building. Where or how the sprinklers are > connected to pipes should not be an issue, as long as adequate water > gets to the fire (with allowance for minimum pipe size, etc). > Semantics over what the definition of a branch line is? I'm waiting > for the AHJ to come at me with the comment that I can't attach a 1" > drop to a 6" main because it doesn't meet the definition of a branch > line. Bill, did someone actually challenge you on this? Tell him the > drop is a 1" branch line looking down and the feed to the pendent > sprinkler off the branch line is fed by an arm-over. > > > > At 09:49 AM 11/23/2007, you wrote: >> Agree with the "why shouldn't we?" but I'm looking for the "where >> does >> it say we can?". Although the simple answer is "we do it all the >> time", >> the 2007 text change language has created a situation where the only >> place to attach a SINGLE sprinkler is a branch line. The 2002 text >> could have been interpreted this way but the 2007 has made it >> explicit. >> >> I have a branch line with 5 outlets. The first two are upright >> sprinklers, the third one feeds two pendents under a duct, the >> last two >> are uprights. >> >> I think all of us would consider this a branch line, but the new >> definition now states that part of this branch line is a cross main >> since the piece under the duct is an independent branch line. Then, >> since the definition of a cross main does not include a sprinkler, >> the >> last two heads have to be piped from a single outlet on the "cross >> main". >> >> Twisted logic I agree but I can't find another definition to get >> me out >> of this AHJ mess. >> >> For a hydraulically calculated system, who cares where you add a >> sprinkler? Can a single sprinkler or a branch line be fed from the >> side >> of a riser as long as you maintain waterflow alarm capability? >> >> Bill Brooks >> >> -------- Original Message -------- >> Subject: Re: Branch Lines / Cross Mains >> From: "Ron Greenman" <[EMAIL PROTECTED]> >> Date: Wed, November 21, 2007 7:24 pm >> To: [email protected] >> >> Just as a standpipe can serve double duty as a sprinkler riser why >> shouldn't a cross-main or feed main also serve as a branch line. >> Ultimately were always talking about one or more standardized >> holes in >> our hose leaking in a defined area. Who cares what size and name you >> use for the hose as long as it will properly support the leaks. >> Enough >> wet guy stuff. Nearly time to eat. >> >> On Nov 21, 2007 12:59 PM, John Drucker <[EMAIL PROTECTED]> >> wrote: >>> For the feed main arrangement is there a method of waterflow >>> detection >>> and annunciation corresponding to the smallest sprinkler ? >>> >>> Happy Thanksgiving all ! >>> >>> John >>> >>> -----Original Message----- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On Behalf Of >>> Roland >>> Huggins >>> Sent: Wednesday, November 21, 2007 3:51 PM >>> To: [email protected] >>> >>> Subject: Re: Branch Lines / Cross Mains >>> >>> certainly. The definitions do not address such hybrid items but that >>> doesn't stop one from doing it. >>> >>> Roland >>> >>> On Nov 21, 2007, at 12:11 PM, [EMAIL PROTECTED] wrote: >>> >>>> Can a sprinkler head be connected to a cross main or feed main >>>> (directly or by way of a sprig, drop, arm over, or return bend)? >>>> >>>> After you answer the question read the revised definition of a >>>> branch >>>> line in 2007, 3.5.1. >>>> >>>> Bill Brooks >>>> >>>> William N. Brooks, P.E. >>>> Brooks Fire Protection Engineering Inc. >>>> 372 Wilett Drive >>>> Severna Park, MD 21146 >>>> 410-544-3620 Phone >>>> 410-544-3032 FAX >>>> 412-400-6528 Cell >>>> >>>> _______________________________________________ >>>> Sprinklerforum mailing list >>>> [email protected] >>>> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >>>> >>>> To Unsubscribe, send an email to:Sprinklerforum- >>>> [EMAIL PROTECTED] (Put the word unsubscribe in the subject >>>> field) >>>> >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >>> >>> To Unsubscribe, send an email >>> to:[EMAIL PROTECTED] >>> (Put the word unsubscribe in the subject field) >>> >>> >>> _______________________________________________ >>> Sprinklerforum mailing list >>> [email protected] >>> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >>> >>> To Unsubscribe, send an email to:Sprinklerforum- >>> [EMAIL PROTECTED] >>> (Put the word unsubscribe in the subject field) >>> >> >> >> >> -- >> Ron Greenman >> at home.... >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >> >> To Unsubscribe, send an email >> to:[EMAIL PROTECTED] >> (Put the word unsubscribe in the subject field) >> >> >> _______________________________________________ >> Sprinklerforum mailing list >> [email protected] >> http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum >> >> To Unsubscribe, send an email to:Sprinklerforum- >> [EMAIL PROTECTED] >> (Put the word unsubscribe in the subject field) > > Todd G. Williams, PE > Fire Protection Design/Consulting > Stonington, Connecticut > www.fpdc.com > 860.535.2080 > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email > to:[EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > > > _______________________________________________ > Sprinklerforum mailing list > [email protected] > http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum > > To Unsubscribe, send an email to:Sprinklerforum- > [EMAIL PROTECTED] > (Put the word unsubscribe in the subject field) > _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field) _______________________________________________ Sprinklerforum mailing list [email protected] http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum To Unsubscribe, send an email to:[EMAIL PROTECTED] (Put the word unsubscribe in the subject field)
